#include <bits/stdc++.h>
using namespace std;
double a[1000010];
int main() {
  int n, s;
  cin >> n >> s;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i <= n; i++) {
    if (a[i] - a[i - 1] > s + 0.5) {
      cout << "No";
      return 0;
    }
  }
  cout << "Yes";
  return 0;
}